Well I was looking at some diagrams last night and found a monostable circuit using a 555 timer module that is triggered by a falling edge which I think might work for my application. This type of circuit I believe would still need a momentary switch to arm it but then is triggered by the high to low voltage change.
I also have the option of using a 0-5v signal to be the triggers for my circuit, if I could build a circuit that armed at anything above x voltage and triggered at anything under y voltage that would be great and eliminate the need for mounting micro momentary switches.
The output would need to be about 12-14v (automotive voltage) and not a very high amperage, I would think only 1 or 2 amps, it is just a small vacuum solenoid being actuated.
Thanks,
Pete